The invention herein relates to a flexible continuous hollow element, whereby the interior space is enclosed by a jacket to permit the transport of media.
Flexible continuous hollow elements of this generic type have been known. Hereinafter, such a continuous hollow element will also be called a hose such as is used in many technological fields for the transport of liquid or gaseous media. When used in air-conditioning systems, for example in motor vehicles, such hoses are used for the transport of coolants. Coolants have the property of being volatile and, if they reach the atmosphere of the earth, they can have harmful effects. In order to prevent such effects, natural coolants, for example CO2, are to be used. Known coolant hoses have the disadvantage of being highly permeable to natural coolants, in particular CO2, allowing the coolant to diffuse through the hose.
Fiber materials, in particular those that have been available under the Gortex tradename, have been generally known. Such fabrics exhibit unidirectional impermeability to water, specifically water vapor.
Therefore, the problem to be solved by the invention herein is to provide a flexible continuous hollow element of the general type as described that exhibits low permeability to CO2 in particular.
In accordance with the invention herein this problem has been solved by a flexible continuous hollow element exhibiting the features of claim 1. Due to the fact that the jacket of the hollow element contains as an integral part a blocking layer, which is impermeable to the medium to be transported and which is formed by a fabric layer creating the interior space of the jacket, permeation through the flexible continuous hollow element is prevented or at least reduced to a negligibly low amount. Therefore, it is possible, in particular if the flexible continuous hollow element is to be used as coolant hose, to transport coolants in such a manner that the coolant cannot escape into the atmosphere. At the same time, a low permeation rate ensures the reliable function of the cooling system that is supplied with coolant.
In a preferred form of embodiment of the invention herein, the mesh width of the fabric layer is smaller than the size of the volatile molecules of the medium to be transported. Therefore, the advantage is achieved that, even after applying the fabric layer, a blocking layer has been created, which leads to the reduced permeability of the jacket.
In another preferred form of embodiment of the invention the fabric layer is woven in a direction radial and axial to the longitudinal axis of the hollow element, or the fabric layer is woven in a direction diagonal to the longitudinal axis of the hollow element. In each case, the alternating weave creates a mesh width that ensures the required impermeability to the volatile molecules of the medium which is to be transported.
Furthermore, considering the preferred form of embodiment of the invention herein, the fabric layer is placed around the jacket layer that forms the interior space, whereby, preferably, the fabric""s longitudinal edges overlap in axial direction. As a result of this, the fabric layer can be applied in a simple layer on the jacket layer.
Furthermore, considering the preferred form of embodiment of the invention herein, the fabric layer is wound around the jacket layer. As a result of this, a flexible continuous hollow element of any desired length can be provided with the fabric layer forming the blocking layer, in that it is wound as a continuous web in the form of a spiral.
Another preferred form of embodiment of the invention herein provides that the fabric layer is woven on the jacket layer that forms the interior space. As a result of this, a particularly tight bond is created between the fabric layer and the interior layer.
A further preferred form of embodiment of the invention provides that the fabric layer is pulled as a shrinkable hose onto the interior layer of the jacket. Consequently, the previously woven shrinkable hose can be pulled over the interior layer, where said shrinkable hosexe2x80x94due to its elongationxe2x80x94adheres tightly to the interior layer of the jacket.
Furthermore, another preferred embodiment of the invention provides that the fabric layer consists of several layers. By superimposing several fabric layers, extremely small mesh widths are created which are impermeable even to relatively small volatile molecules. In so doing, the flexible hollow element exhibits extremely low permeability.
By configuring the blocking layer as a fabric layer, the overall flexibility of the continuous hollow element remains unimpaired by the blocking layer. Therefore, the fabric layer, due to its inherent properties, can readily adapt to bending stress created by the hollow cylinder, without impairing the effect of blocking the volatile molecules.
For example, a particularly suitable fabric layer is a microfiber fabric that can block low-molecular media. Furthermore, for example, semi-permeable membranes which are produced from a woven fiber fabric (microfiber weave) can be used, whereby these are at least unidirectionally impermeable to the low-molecular molecules of the coolant medium that is to be transported.
Additional preferred embodiments of the invention herein exhibit the remaining features as disclosed by the Subclaims.